Method of extracting oil



Patented Aug. 5, 19 24.

. City, State of e MARYLAND.

METHOD OF EXTRAGTING OIL.

No Drawing. Application filed July 8, To all whom it may concern:

Be it known that I, CARL DREYMANN, a citizen of Germany (who has filed first and second U. S. citizenship papers), at Baltimore, in the county of Baltimore Maryland, have invented certa1n new and useful Improvements in Methods of Extracting Oil; and I do hereby declare the following tobe a full, clear, and exact description 'of the invention, such as will enable others skilled in the art towhich it appertains to make and use the same.

' This invention relates to improvements in the extraction of oils and fats from oilcontaining or fat-containing materials with the aid of a solvent. The invention isof particular advantage in the extraction of materials containing water in greater or less amount, such as bones, tankage, garbage, oil seeds, etc. I

During the extraction. of such oil-containing materials, by means of a solvent, the water is separated to a'greater or. less extent during the extraction and is drawn ofl" in admixture with the solvent. This water. contains soluble organic material dissolved in it, and, when the solvent is evaporated; or is used repeatedly for the extraction, this dissolved organic material causes discoloration of the fat. 4

According to the present invention, this objectionable discoloration of the fat is avoided or reduced to a minimum. This is effected by removing the solvent from the extraction apparatus, together with admixed water, separating the water from the solvent, and returning the water-free solvent to the; extraction apparatus, thereby keeping the solvent in continuous circulation and preventing any prolonged contact of the contaminated water with it. The resultin solution of the oil or fat in the solvent 1s thus obtained in a substantially water-free state,- and the solvent is then evaporated to give the fat or oil which is thus obtained without objectionable contamination or discoloration and of a lighter color and more agreeable odor.

In the practice of the invention, the oilcontaining, or fat-containing material may be charged into a suitable extracting vessel or tower and the solvent introduced continuously at the to of the apparatus and permitted to rco ate down through the material, there ysextracting the oil or fat.

The resulting solution of oil or fat in the residing top and caused to flow gradually increased, the

a the counter-current 182%., Serial Ito. 895,068.

solvent collects in the bottom of the apparatus, together with the water which is separated from the-material at the same time and wh ch: contains nitrogenous organic matter dlssolved therein. Instead of recirculatlng the entire amount of solvent" and admixed water for efi'ecting further extraction, and thereby keeping the contaminated water 1n prolonged contact with the solution of fat and permitting the nitrogenous matter in solution to be absorbed'by and contaminate and discolor the fat, the water and solution are drawn oil from the bottom of the apparatus and the water is separated from the solution. This separation can be effected in, a suitable separator, in which the water is automatically separated, and. the water-free solvent, with the oil or fat dissolved therein, is returned to the top of the extractor to effect further extraction therewith. This extraction and separation can be carried out .in a continuous manner by pumping the solvent and admixed water from the lower part of the extractor into a separator and pumping the water-free solvent from the separator back to the top of the extractor, thereby keeping the solvent in continuous circulation and freeing it from water without permitting prolonged contact of the contaminated water therewith.

The improved process of the present invention can be carried out in different types of apparatus, as will be readily understood. Apparatus of the character above referred to, that is, an extraction apparatus arranged so that the solvent can be introduced at the down through the body of material to be extracted, with resulting collection of the solvent and admixed water at the bottom, is well adapted for use in the practice of the invention.

The solvent-can be repeatedly recirculated through the apparatus and its fat content water being sepaeach recirculation. can be carried out on principle by subjecting successive bodies of material to extraction with the same solven, and separating the admixed water from the solvent before it is rated therefrom during So also, the extraction passed from onebody of material to the i traction of the partially boihng'point can thus be used for the extraction.

The extraction can be carried out at ordinary temperatures, or the solvent action can be increased by proper heating.

When a solution of the oil or fat in the solvent is obtained in the manner described, with a sufiicient' oil or fat content, the waterfree solution is subjected to evaiporation for the separation of the solvent rom the oil or fat. Owing contaminated water in admixture with the solvent, both during the extraction and the subsequent evaporation, the resulting oil or fat is light in color and of more agreeable odor for the reason that it contains less contaminating organic impurities dissolved therein. The' advantages of the invention are especially marked in the extraction of materials such as" old bones, garbage, fish ofial, and other low grade materials, which contain appreciable, amounts of readily soluble nitrogenous organic matter and appreciable amounts of water which may be saturated with such soluble material. By carrying out the extraction according to the present invention, tained in the water are prevented from having any continued contaminatingor objectionable action upon the fat being extracted.

I claim-:- v 1. The method of extracting oils and fats from materials containmg them and also to the substantial absence of these soluble impurities con- 7 containing water, which comprises subjecting such materials to extraction with a solvent of the oil or fat, withdrawing the resulting fat solution and admixed water, separating the water from the solution of the oil or fat in the solvent, and returning the resulting water-free solution for further extraction.

2. The method of extracting oils and fats I from materials containing them and also containing water, which comprises subject-v in such materials to extraction with a suitab e-solvent of the oil or fat, continuously separatin solution uring extraction, and evaporating the solvent from the water-free solution.

3. The method of extracting oils and fats water from the resulting solvent from materials containing them and also containing water, which'comprises subjecting such materials to repeated extraction with a suitable solvent of the oil or fat, withdrawing the solvent after each extraction and separating the water therefrom, and returning the water-free solvent for further extraction. I

4. The method of extracting oils and fats from materials containing them and also containing water, which com rises subjecting the body of such materia to extraction with a suitable solvent of oil or fat, withdrawing the resulting solution and admixed water, separating the water from the solution, returning t traction and repeating the extraction and separation of water until a solution of high fat content is obtained, and evaporating the solvent from the extracted fat.

In testimony whereof I aflix my signature.

CARL DREYMANN.

e solution for further ex- 

